In the prior art, during a display procedure of an organic light-emitting diode (OLED for short) display device, an electric field of a long-time loaded DC driving voltage causes polarization of OLED internal ions, and formation of a built-in electric field, which increases an OLED threshold voltage, greatly reduces luminous efficiency of the OLED, and shortens lifetime of the OLED.
As shown in FIG. 1, an existing 2T1C pixel unit driving circuit includes an input transistor T1, a storage capacitor CS, and a driving transistor T2. In FIG. 1, T1 and T2 are n-type transistors; VSCAN and VDATA are respectively a scan voltage and a data voltage; T2 is used to drive the OLED; and VDD and VSS are respectively a high level and a low level.
During operation of the 2T1C pixel unit driving circuit as shown in FIG. 1, when VSCAN is at a high level, data voltage VDATA is applied to T2 through T1, to activate T2. At this time, an anode of the OLED has a potential of (VDATA-Vth-VOLED), wherein Vth is a threshold voltage of T2, and VOLED is a voltage difference between the anode and a cathode of the OLED. When VSCAN is at a low level, a voltage stored in CS can still activate T2.
It can be seen from the above, the 2T1C pixel unit driving circuit as shown in FIG. 1, after being applied with data voltage VDATA through a data line, will be in a light-emitting display state during one whole frame of time. A long-term DC bias light-emitting state of the OLED accelerates polarization of organic materials, thereby enhancing the built-in electric field of the OLED, increasing the OLED threshold voltage, remarkably reducing the luminous efficiency of the OLED, and shortening the lifetime of the OLED.